Can't Boot from Snow Leopard anymore after having installed mavericks on an external HDD

Question

Can't Boot from Snow Leopard anymore after having installed mavericks on an external HDD

Hi,

I have a Macbook Pro running Mac OS X 10.6.

I wanted to test how mavericks works on my computer so I downloaded the OS and then I installed on a external USB HDD. Everything work as expected. I can now boot from the USB device with mavericks and I still see my internal HDD (containing Snow Leopard) with all the data untouched.

The problem is that I can't boot anymore from my internal HDD, even if the usb drive is not connected, I can see that the boot is "mavericks-style" and then fails because it doesn't find the drive. It seems that the installation procedure not only installed mavericks on the external drive, but also overwrites the boot sector of the internal HDD? How can I boot again my MBP with Snow Leopard?

Thanks in advance.

Eugenio

MacBook Pro, Mac OS X (10.6.8)

Posted on Jul 5, 2015 8:00 AM

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Answer 1

Eric Root

Level 10

684,039 points

Jul 5, 2015 8:14 AM in response to eugenio_from_here

Try booting holding down the option/alt key. Can you select Snow Leopard there?

What happens when you restart with the external drive not attached?

Startup Issues - Resolve

Startup Issues - Resolve (2)

Startup Issues - Resolve (3)

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Answer 2

Lexiepex

Level 6

14,102 points

Jul 5, 2015 8:30 AM in response to eugenio_from_here

In SystemPreferences is an applet called "Startup Disk": open it and set the SnowLeopard disk as to start from, then restart.

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Answer 3

Jul 5, 2015 8:32 AM in response to Eric Root

Hi Eric,

no, booting with ALT doesn't show Snow Leopard, just the external USB drive. The internal HDD drive, however, is still there with all the data (I can see it I boot with mavericks).

If I boot without the external drive connected I can see a loading bar (but it's a mavericks loading bar, not a Snow Leopard Loading bar, which means that something has been written also into the internal HDD) but at some point the boot failed because it doesn't find the external drive (I can't remember the error message, if it's useful I can re-boot and post it).

Thanks.

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Answer 4

Jul 5, 2015 8:46 AM in response to Lexiepex

LexSchellings wrote:

In SystemPreferences is an applet called "Startup Disk": open it and set the SnowLeopard disk as to start from, then restart.

Perfect, fixed, thanks!

Now I am curious to understand where is the boot loader related to mavericks stored. When I installed mavericks I set to install it in the external drive, but actually it stores some "launch script" on the internal drive too? It means that if I connect the external drives to another computer I can't boot from it?

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Answer 5

Lexiepex

Level 6

14,102 points

Jul 5, 2015 9:35 AM in response to eugenio_from_here

Normally you access this bootloader with starting holding Alt(option) like Eric said. I don't know why this did not work with you, but try it again now.

Lex

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